and twenty feet high, with doors at the top for entrance of the char and
openings at the bottom through which it is removed. There are also many
pipe connections for the introduction and outlet of liquors, steam, hot
water and compressed air. The filters are insulated on the outside with
asbestos or some other non-conductor of heat to prevent the temperature
of the liquor from being lowered as it passes through. Each filter has a
capacity of from sixty thousand to eighty thousand pounds of bone-char.
At the bottom of the filter is a perforated iron plate. Over this is
placed a coarsely woven cotton blanket, through which the liquor will
pass, but which prevents the char from escaping from the filter with the
liquor or wash water. After the blanket is set in place, the char is
delivered by gravity through an overhead pipe into the filter, until it
is entirely full. The char, as it goes in, has a temperature of from 170
to 180 degrees Fahrenheit, and the bag-filtered liquor which is then run
on has a slightly higher temperature.
[Illustration: CHAR FILTERS]
[Illustration: CHAR FILTERS—SHOWING OUTLET PIPES]
When the liquor in the filter reaches the top and the char has settled
in a compact mass, the cover is put on and fastened securely to prevent
leakage. The liquor is again allowed to run into the filter by gravity,
from the tanks about fifteen feet overhead. The valve on the bottom of
the filter is then opened and the liquor, as it filters slowly through
the char, is led through a copper pipe to the liquor gallery, to which
station all the char-filtered liquor is delivered. This pipe, instead of
leading downward from the filter, leads upward and nearly to the top, so
that the flow of liquor through the char will be slow and uniform and the
filter will always remain full of liquor. The diameter of the filter is
ten feet, while that of the outlet pipe is two inches, so that the flow
of liquor through the char is necessarily very slow. The reason for this
is that the liquor must remain in contact with char a certain time to
enable the char to absorb the coloring matter and soluble salts.
The first liquor from the filter appears cloudy and is sent back for
refiltration, but it soon becomes bright, perfectly colorless and
transparent as plate glass. This white liquor is pumped from the liquor
gallery into the tanks on the top floor in the pan house, ready for the
next process, which will be dealt with presently.
After a filter has been running for from twenty-four to thirty-six
hours, depending on the character of the sugar in the liquor, the char
becomes “tired” or spent. In other words, it has absorbed so much of
the impurities and coloring matter from the liquor passing through it
that its capacity to absorb more is gone and the liquor begins to show
a slight straw or canary color. The inspector in the liquor gallery
immediately notices this and orders the liquor stopped. Immediately
afterwards a lower-grade liquor is turned into the filter, which forces
the first liquor out before it. In due time the man at the liquor gallery
notices the number two liquor coming from the filter and turns it into
separate tanks. In time a still lower grade of liquor is turned on and
the filter run until the bone-char is absolutely exhausted, when it is
ordered “sweetened off.”
Hot water is then turned in at the top of the filter to wash out the
remaining sugar liquor which gradually becomes more and more dilute.
When its density has been lowered to about thirty-five per cent of solid
matter, it is diverted to other tanks, and this is continued until only
three-tenths of one per cent of sugar remains in the sweet water, as it
is now called. The washing of the char in the filter in this manner, by
hot water, is kept up for twelve hours, but as soon as the sugar content
falls below three-tenths of one per cent the solution is allowed to run
to waste, as the recovery of this small percentage of sugar would cost
more than its value.
The sweet water is sent to the evaporators, concentrated to 58.6 per cent
of solid matter, and it then begins its refining journey over again.
This long and continued washing of the filters is for the purpose of
removing as much as possible of the organic and mineral impurities
absorbed by the char.
The washing completed, compressed air is applied to the filter to force
out the remaining water. The bottom doors of the filter are then opened
and the char, containing about twenty per cent of water, drops to the
floor below. Here it passes through mechanical driers and is delivered
comparatively free from moisture to the kilns. There it is revivified,
that is, the organic matter in the char which could not be removed by
washing is converted into carbon by being heated to a cherry red in the
absence of air. This is accomplished by allowing the char to pass by
gravity through the red-hot retorts of the kilns.
As the wet char leaves the filter, it drops on a moving belt which
carries it to large cast-iron hoppers leading to the driers immediately
beneath, where the greater part of the moisture is expelled from the char
prior to its being treated in the revivifying kilns. The driers are made
up of a number of thin, hollow, cast-iron, triangular pipes, enclosed in
a large, rectangular, outside casing. The wet bone-char passes over these
hollow pipes as it falls slowly through the drier. The hot gases from the
furnaces of the kilns below pass through these cast-iron pipes, giving
off heat as they ascend, thus driving off the moisture in the char as
it falls down over the outer surface of the pipes. At the same time, hot
air obtained from cooling the char in the cooling pipes below the retorts
is drawn through the drier, coming in direct contact with the char. The
moisture given off by the char is absorbed by this hot air and carried
out of the drier and building by fans or smokestacks. By this means the
water in the char is reduced to ten per cent, and in this comparatively
dry, hot state it runs freely by gravity from the bottom of the drier
into a second set of hoppers, through which it drops into the retorts of
the kiln. The hot gases, after drying the char, pass out at the top of
the drier through a flue leading to a stack outside the building.
[Illustration: TOP OF CHAR FILTERS—SHOWING PIPE CONNECTIONS]
[Illustration: EXTERIOR VIEW OF CHAR DRIER]
The kilns are large square boxes of brick, built around a strong
supporting iron structure. On each side of these boxes are a number of
large flat pipes of cast iron, nine feet long and twelve inches by three
inches in section, the iron being three-quarters of an inch thick. These
pipes are called retorts and are arranged vertically in the kilns, forty
on each side. The space in the center between the retorts is known as
the furnace and extends the entire length of the kiln, a distance of
about sixteen feet. Intense fires are maintained in this central space
and the flames playing around the retorts keep them red-hot. The upper
ends of the retorts lead into the hoppers above and the lower ends to the
cooling pipes below. As the char passes gradually through the red-hot
retorts, it becomes heated to 900 degrees Fahrenheit and the organic
matter it absorbed from the sugar liquor is changed into carbon. In
this way the char becomes almost as good as new, or, as the term goes,
revivified. Each kiln has a capacity of revivifying sixty thousand pounds
of bone-char per day.
If the char in this red-hot state were suddenly exposed to the air, the
contact with oxygen would bring about combustion and the char would be
quickly reduced to ashes, so a cooling process is necessary. It is,
therefore, drawn from the cast-iron retorts into cooling pipes located
directly beneath. These pipes are of thin sheet-iron and are about three
by four and a half inches in section. There are three under each retort,
and a mechanical device at the bottom allows only a small amount of
char to escape at a time. This amount can be regulated at will by the
operator, and in this way the char is held in the retorts the exact time
necessary for its revivification.
A current of cold air circulates continually around the cooling pipes,
taking up the heat from the char and delivering it through pipes to the
drier overhead, so that when the char leaves the bottom of the pipes its
temperature is about 180 degrees Fahrenheit. From the cooling pipes, it
drops on a belt conveyor from which it is carried by endless belt or
chain bucket elevators to the top of the char filters to be used again.
The manipulation of the char filters varies in different refineries,
some running the liquor over the char for a longer period than others,
but a fair average of the time required for filling, settling running
liquors and syrups, sweetening off, washing, applying air and emptying,
is eighty-six hours, the shortest time being seventy-two hours. Taking
eighty-six hours as a basis, it will be seen that the char is handled
and revivified eighty-one times each year after making due allowance for
Sundays, holidays and annual clean-up periods.
Each time the char is handled, a certain amount of it is broken into
dust, and this is taken out by passing it over fine screens, and also by
exhaust fans. Obviously, the amount of dust taken out each day must be
replaced by its equivalent in new char. It is estimated that the original
char put into the filters will last from five to six years before it
finally becomes disintegrated and is taken out as dust.
[Illustration: INTERIOR ARRANGEMENT OF CHAR DRIER]
[Illustration: EXTERIOR VIEW OF CHAR KILNS—SHOWING OIL-BURNING APPARATUS]
As approximately one pound of char is required for every pound of sugar
melted, it will be seen that as the liquor is in contact with the char
for only twenty-four hours out of seventy-two, a refinery turning out
two million pounds of sugar per day should have filter capacity for six
million pounds of char. The amount of the latter that is handled each
year is, therefore, very great and requires a large and costly plant to
take care of it properly.
CRYSTALLIZATION
PRODUCTION OF CRYSTALS BY CONCENTRATION
The refining process has been described up to and including the
purification and decolorizing of the sugar liquor, the last step being
the delivery of the pure white liquor into the receiving tanks in the pan
house.
After the white liquor leaves the char filters, the greatest care must be
exercised to keep all the machinery, piping and apparatus scrupulously
clean, for if any foreign matter becomes mixed with the liquor or sugar
it can only be removed by refiltering or remelting.
By means of vacuum, the liquor is drawn from the tanks into the vacuum
pans, this being the last operation in which the sugar is handled in a
liquid state. From this point on it drops by gravity from floor to floor
in a solid or semi-solid form, until it reaches the packing room as a
finished product. In a first-class refinery, the vacuum pans, as well
as all the piping through which the liquor passes, are made of copper
instead of iron and steel, which eliminates the possibility of rust or
scale getting into the sugar.
Refinery vacuum pans are usually from fourteen to sixteen feet in
diameter and from sixteen to seventeen feet high, while in shape they
appear almost spherical. The boiling takes from one hour and twenty-five
minutes to one hour and forty-five minutes, and about forty-five tons
of granulated sugar can be made at each boiling in a fourteen-foot
pan. Before the liquor is drawn in, the pan is thoroughly cleansed
with hot water and steam. All openings are then closed and the vacuum
pump started. The air is quickly exhausted, a valve in the pipe line
leading from the receiving tank is opened and the pan is given a charge
of liquor. Steam is turned into the coils of the pan and the boiling
process begins. Soon sufficient moisture is driven off to cause the sugar
to “grain.” Shortly after the grain forms, another charge of liquor is
drawn into the pan and the operation is repeated until the pan is full
of a thick, white, mushy substance called massecuite, that looks very
much like half-formed ice. The vapor driven off in the boiling passes
out through a large pipe at the top of the pan and is condensed by being
sprayed with cold water. On account of the high vacuum, the liquor
boils violently at temperatures ranging from 140 degrees to 195 degrees
Fahrenheit; thus the risk of scorching, discoloration or caramelization
of the sugar is minimized.
On the front of the pan is a vertical row of windows made of heavy
plate-glass, and through these the liquor is watched during the boiling.
The massecuite in the pan is sampled at intervals by the sugar boiler,
by means of a “proof stick,” a brass rod about three feet long and one
and one-quarter inches in diameter, in the pan end of which there is a
hollow space. This stick is pushed through an opening in the side of
the pan into which it fits tightly, and then partly withdrawn. A small
quantity of the contents of the pan remains in the hollow space, and
this the sugar boiler removes and places on a piece of clear glass. On
holding it up to the light, he sees exactly how the crystallization of
the sugar is progressing, and by observing and feeling the crystals, he
is enabled to control the boiling perfectly. When he concludes that the
evaporation is complete and the massecuite of the proper consistency, the
pump is stopped and the vacuum broken by opening a valve near the top
of the pan, admitting the outside air. The foot valve is then opened
and the massecuite drops from the pan into a mixer directly underneath.
There it is kept constantly in motion by a revolving shaft with paddles,
to prevent the crystals from sinking to the bottom. From the mixer it is
drawn into the centrifugals and purged of the mother liquor, the pure
crystals being left in the machine. The liquor thus drawn off contains
whatever impurities may have remained in the original liquor. It is
now pumped back and run through the char filters again, after which it
is boiled in the vacuum pan and the granulated sugar taken out in the
centrifugals. This completes the process of producing crystallized sugar
by concentration.
[Illustration: A REFINERY VACUUM PAN AND PUMP]
[Illustration: ARRANGEMENT OF STEAM COILS IN A VACUUM PAN]
There are many interesting and intricate problems in connection with the
extraction of the sugar from the wash waters, sweet waters and low-grade
syrups that are constantly accumulating in a sugar refinery, but space
will not admit of their being dealt with here. Suffice it to say that the
process of extraction is carried to a point where the sugar recovered
barely pays for the labor and fuel expended in the operation. The
ultimate result is white sugar, table syrup and molasses.
This molasses is used largely in the manufacture of vinegar and alcohol.
Mixed with grain and alfalfa meal, it makes an excellent stock food that
cattle take to readily and that possesses high value as a fattening
agent. The sucrose and glucose content of molasses as it leaves the
refinery is about fifty per cent.
Naturally, in a process involving so much handling, filtering and
boiling, there must be some loss, and the efficiency of a refinery is
based upon the percentage of granulated sugar recovered from the raw
article delivered to the melt. It may be stated for general guidance
that, taking an average of the refineries of the United States, one
hundred pounds of refined white sugar is made from each one hundred and
seven pounds of ninety-six-degree raw sugar melted. Some of the sugar
lost is accounted for in the molasses, in the sediment from the filter
presses, and in the wash waters from the char filters. The remainder is
the undetermined loss in handling, in sugar destroyed by heating, and in
sugar dust escaping during the manufacturing operation. As has been said,
the component parts of raw sugars vary more or less, and the recovery in
white sugar from two lots of raws, each polarizing ninety-six degrees,
might differ considerably according to the refractory matter in the
original raw sugar.
The following figures give a fairly accurate idea of the disposition of
one hundred pounds of ninety-six-degree raw sugar in refining:
Water, which is eliminated .70 per cent
Non-sugar, which is eliminated 3.30 ”
Sucrose loss, undetermined .75 ”
Sucrose left in molasses 1.75 ”
Sucrose extracted in granulated form 93.50 ”
------
Raw sugar melted 100.00 ”
The undetermined loss includes every loss from the time the raw sugar
is weighed into the warehouse until the granulated article is sold to
the buyer. It is evident, therefore, that one of the principal items
of refining cost is the actual loss of weight in converting raw into
refined sugar. Assuming that the raw sugar costs four cents per pound,
the refiner has lost on each one hundred pounds melted, four cents ×
6½ pounds, or twenty-six cents, less the small value of the resulting
molasses. If the raw sugar cost six cents, the loss would be thirty-nine
cents. At four cents, the loss is equivalent to $5.20 per ton, or, in
the case of a refinery melting two million pounds of raw sugar daily,
$5,200.00 for each working day. This does not include any of the
operating expenses, such as labor, fuel, bone-char, containers, selling
expense or administration—just the actual value of the raw sugar lost in
the process of refining.
[Illustration: REFINERY CENTRIFUGAL MACHINES]
[Illustration: EXTERIOR VIEW OF SWEATER]
PARTIAL DRYING
PURGING CRYSTALS FROM THE SYRUP
Returning to the sugar left in the centrifugals, the force developed
in a machine forty inches in diameter, spinning at the rate of eleven
hundred revolutions per minute, is so great that it quickly dispels all
the liquor surrounding the crystals, leaving them nearly dry, in a solid,
vertical wall. Water, filtered to insure its purity and cleanliness,
is then sprayed on this spinning wall of sugar, only to be immediately
thrown off through the sugar by the centrifugal motion. In passing
through the sugar it washes the last of the syrup from the grains and
leaves them perfectly white. Cold water, rather than hot, is used for
this purpose, as it dissolves less sugar.
In former years a small quantity of bluing was added to the spraying
water in order to enhance the whiteness of the sugar, just as bluing is
employed in washing fine linen fabrics. Since the pure-food laws became
effective, however, the practice has been discontinued in all cane-sugar
refineries.
After the sugar is thoroughly washed, the centrifugal machine is stopped,
a large valve in the bottom opened and the mechanical discharger rapidly
ejects the sugar (now containing only about 1.2 per cent moisture) from
the machine into a storage bin beneath.
FINAL DRYING OF CRYSTALS
For some reason not well understood, the next step in refining is called
“granulation.” Actual granulation, or crystallization, takes place in the
pans, and the process about to be described should properly be called
drying. The manufacturing term, however, is as given.
Drying is effected in an apparatus consisting of two large cylindrical
drums of wrought iron. These drums are about six feet in diameter, thirty
feet long and have a slight downward pitch from the receiving to the
discharging end. The first drum rests on the floor, directly below the
storage bin, and is called the sweater. It turns slowly on revolving
wheels, by means of circular tracks bolted to it. The power that moves it
is delivered from an electric motor, through a pulley, shaft and pinion,
the latter working in a gear bolted to the outside circumference of the
drum. Fastened to the inner surface of this drum is a series of short,
narrow shelves with saw-tooth edges that serve to carry the sugar to the
top of the revolving cylinder, whence it falls to the lower side, causing
a continual shower of sugar throughout the entire length and breadth
of the drum. The sugar is delivered through a pipe at the upper end of
the sweater, and the revolving motion together with the incline of the
cylinder gradually works it down to the lower end. Here it drops through
a chute to the granulator on the floor below, where the process of drying
is completed.
A strong current of hot air is drawn through the sweater by a powerful
fan connected to the upper end by a very large pipe. The air introduced
in this way is brought to a high temperature by passing around a number
of coils of pipe charged with steam, which are placed directly in front
of the sweater. The hot air sweeping through the drum absorbs nearly all
of the moisture in the sugar, which carries 1.2 per cent of water when it
enters the drum and about 0.1 per cent as it leaves it.
The granulator, or lower drum, is the same size as the sweater and is
constructed in very much the same manner, having shelves for carrying the
sugar to the top and dropping it at the proper point, and being equipped
with a large fan to draw off the hot, moist air. Instead of having
steam coils in front, however, it has in its center a steam-heated drum
about twenty-four inches in diameter that revolves with it. The sugar
crystals, as they fall in a shower from the shelves, come in contact
with the hot inner drum on their way through the granulator, and in this
manner become thoroughly dried. The moisture in the sugar, as it emerges
from the granulator, is less than four-hundredths of one per cent, an
amount too slight to determine except with the most delicate apparatus.
[Illustration: FRONT VIEW OF SWEATER—SHOWING STEAM COILS FOR HEATING THE
AIR]
[Illustration: INTERIOR VIEW OF SWEATER]
To insure perfect drying, the damp sugar must be fed to the upper drum
or sweater with unfailing regularity. This is accomplished by the use of
revolving screws located under the storage bins. By turning a certain
number of revolutions per minute, they deliver an even and steady supply
of sugar.
From the granulators the sugar is dropped on thin cotton belts that,
passing around highly magnetized pulleys, carry it to the dry storage
bins. The sugar is cooled to normal temperature before being packed
in containers, thus preventing subsequent absorption of moisture and
consequent caking.
Magnetic pulleys are used to extract any particles of iron scale or rust
that may drop into the sugar after the liquor leaves the char filters.
Rust sometimes forms in the pans, mixers, conveyors, elevators, sweaters
or granulators, and should it get into the sugar the magnetic pulleys
will surely remove it.
Storage bins and storage tanks are prominent accessories of all sugar
refineries, for if a breakdown should occur at any point, there must
always be a supply of material on hand to keep the refining operations
going while the trouble is being remedied.
SCREENING
SEPARATING CRYSTALS INTO VARIOUS SIZES
The now thoroughly cold, dry and free-running granulated sugar is drawn
from the storage bins through galvanized metal pipes and taken to the
separators by screw conveyors, which deliver it at an even, steady feed—a
most essential feature. The sugar as it comes from the pans is made up
of crystals of various sizes. It also contains a number of small lumps
formed in the centrifugal machines, or in some part of the process after
it leaves the pans. It is necessary to separate the crystals according to
size and to screen out the lumps, for the following reason:
In some parts of the country, people have been educated to use a
coarse-grained sugar; in other sections, they are accustomed to sugar of
a fine grain. For example, on the Pacific coast, the demand is for the
fine-grained article; the consumers of the Mississippi river valley like
a fairly large grain; while the Atlantic coast trade calls for a still
coarser product. There is a difference, too, as to containers. In the
East the preference is for the barrel package, while the Western buyer
wants his sugar put up in bags.
There are many different types of separators commonly in use, but in all
of them the governing principle is the same. It is the elimination of
lumps and dust from the final product and the separation of the sugar
crystals according to size. The separator here specifically referred to
will explain the principle as well as any other type, and a glance at
the accompanying illustration will give the reader a good idea of its
construction. It is made up of a number of wire screens of various sizes,
fixed at a sharp incline, one above the other, and all enclosed in a
tight, dust-proof steel case. At the top of the case is a steel screw
conveyor by which the sugar is fed evenly and steadily across the entire
width of the top screen.
On the outside face of the case are a number of shafts to which hammers
are attached. As the shafts revolve, the hammers tap the various screens
below, lightly and at rapid intervals, thus causing them to vibrate.
[Illustration: SEPARATOR—CLOSED, READY FOR OPERATION]
[Illustration: SEPARATORS, ONE OF WHICH IS OPEN—SHOWING THREE SCREENS FOR
SEPARATING THE SUGAR GRAINS]
The upper screen, called the scalper, is quite coarse and allows all the
sugar to fall through except the lumps, which run down the face of the
screen into a pipe that carries them to the melt, where they begin the
refining process over again. These lumps, however, represent a very small
proportion of the whole.
The second screen is finer than the scalper. It permits part of the sugar
to pass through, but retains a certain amount which falls down on the
face of the screen, whence it is led through a pipe to a special bin.
Sugar of this size is known as coarse granulated.
The next screen lets the finer grains drop through, but catches the
standard granulated, which in turn is drawn off to its special bin. The
last screen, an extremely fine one, retains the extra fine granulated,
and this in turn is delivered to its appointed bin. The sugar passing
through the last screen is so fine as to be classed as “dust,” which, not
being marketable, is usually remelted.
The amount of any one grade of sugar obtained from the separator may be
changed, within certain limits, by the boiling in the vacuum pans. If a
large proportion of fine-grained sugar is required, the sugar boilers
are instructed accordingly. It is impossible, however, to boil all the
grains in each strike a uniform size, or to boil any two strikes exactly
alike, so the separators are necessary, especially for removing the lumps
and dust. The dust is caused by the constant falling of the dry sugar
crystals against each other in the driers and granulators, and by the
grinding action upon the sugar crystals in the screw conveyors.
PACKING
FILLING VARIOUS KINDS AND SIZES OF CONTAINERS
When putting up his goods, a sugar refiner—like every other
manufacturer—must needs cater to the wishes and tastes of the consuming
buyer. The modern tendency in containers is in favor of sealed air-tight
and dust-proof packages. Some refiners spend great sums of money every
year in advertising the merits of special sugars packed in dust-proof
cartons. Their rivals generally follow suit, as competition in the
marketing of sugar is probably far keener than in any other line of
business.
The plain truth is that all refined granulated cane sugar offered
for sale in the markets of this country today is almost identical,
irrespective of the manner in which it may be packed. The poorest quality
of refined sugar made has, in all likelihood, a purity not lower than
99.5 per cent, while the highest grade cannot possibly exceed 99.9 per
cent, a difference of only four-tenths of one per cent, hence it is
evident that all refined sugars are practically pure, the fancy package
simply meaning a fancy price.
The methods of transporting and handling the sugar after it leaves the
refinery may justify the additional expense, but this is subject to
argument. However, it makes but little difference to the manufacturer, as
the cost of the package as well as the extra handling is always included
in the selling price.
A few years ago all sugar went out in barrels or bags, while today a
modern refinery turns out about twenty different styles of container, and
twenty-four kinds of sugar. It is obvious, therefore, that the packing
room of a refinery is an interesting place, covering as it does a large
area and including a great amount of special, intricate machinery for
filling, weighing and sewing or sealing packages.
In the bottom of the bins into which the sugar is delivered from the
separators is a series of galvanized iron pipes, through which the sugar
runs to the various filling devices, the latter being usually arranged in
long rows. Under the end of each pipe is an automatic weighing machine.
In packing bags, a workman hangs a bag on the weighing machine and
presses a lever, thus allowing the sugar to run into the bag. As soon
as the exact amount required is reached, the flow is automatically cut
off. These weighing machines are so accurate that they gauge the amount
to within a fraction of an ounce. The operative removes the full bag,
places it on a conveyor that runs in and level with the floor and quickly
adjusts an empty one on the weighing machine. These men become so expert
that a single operative will fill two hundred and fifty one-hundred-pound
bags per hour. The weighing machines are designed to fill and weigh four
hundred and eighty one-hundred-pound bags per hour, but the operative
cannot handle them at this rate.
[Illustration: FILLING, WEIGHING AND SEWING 100-POUND SACKS]
[Illustration: FILLING, WEIGHING AND SEWING 25-POUND SACKS]
Four sewing machines, specially designed for sewing the filled bags,
are located immediately over the conveyor and in direct line with it.
As the bag passes along on the conveyor, the operative at the first
machine picks up the end of the inner cotton sack and passes it through
his machine, stitching it securely. The bag then passes along to the
third machine, where the operative takes hold of the outer burlap bag and
sews it in the same manner. Each operative has a spare machine ready for
instant use in case the one he is running gets out of order. Continuing
its journey to the end of the conveyor, the bag is deposited on the main
belt conveyor, which takes it without manual aid to the shipping floor
or the storage warehouse. A sewing-machine operative will sew as many
as seventeen bags per minute, but it is trying work and the men relieve
each other at intervals during the day. Both the one-hundred- and the
forty-eight-pound sacks are handled in this manner. Formerly the half
sacks weighed fifty pounds, but since the Parcel Post law went into
effect they have been changed to forty-eight pounds to permit of their
shipment by mail. Those containing twenty-five, ten, five and two pounds
are weighed and sewed in much the same way, by the aid of specially
designed, rapid-handling machinery. The small package machines will
accurately weigh and fill five-pound bags at the rate of twenty-five
packages per minute, the others in proportion.
The paper boxes, or cartons as they are called, are weighed and filled
by special machinery. This machinery seems to possess an intelligence
almost human. One girl feeds the cartons (the tops and bottoms of which
are open) into the machine at the rate of thirty-two per minute. The
machine glues the bottom, weighs the sugar to within one thirty-second of
an ounce, fills the carton, glues the top, seals it and passes it on to a
conveyor which delivers the finished package to a table, from which it is
packed into a box for shipment. Women are usually employed in putting up
the lighter packages.
A short distance from the bag-weighing machines, and running parallel
with them, is a line of pipes or spouts for filling barrels. On the floor
under each spout is a barrel shaker. This is a heavy cast-iron plate
that is lifted about one inch, first on one side, then on the other, by
the action of two cams or arms attached to a revolving shaft underneath.
The shaker drops back violently on the supporting frame after each lift,
causing the sugar to settle compactly in the barrel as it is filled to an
average weight of three hundred and fifty pounds. Naturally, the greater
the amount of sugar packed in a barrel, the less the container costs per
unit of output, and as the average cost of a sugar barrel in the United
States is fifty cents, the container cost per one hundred pounds of sugar
is 14.3 cents.
Without the shaker, not more than three hundred and thirty pounds of
sugar could be put in a barrel, which would increase the cost per one
hundred pounds to 15.1 cents. This difference on a single day’s output of
two million pounds represents one hundred and sixty dollars, an eloquent
argument in favor of the shaker.
[Illustration: FILLING BARRELS]
[Illustration: METHOD OF HANDLING BARRELS]
In packing barrels, the operative first lines the barrel with heavy
paper to prevent the sugar from coming in contact with the rough wooden
sides and to keep it from sifting out between the staves. The barrel,
thus lined, is placed on the shaker, a valve on the spout opened and
the shaking barrel filled to the top. The barrel is then removed and
turned over to the cooper, who heads it up and rolls it on the scale for
weighing.
Before an empty barrel reaches the packing room, it is weighed and the
weight (generally from nineteen to twenty-five pounds) is stamped on
its side. The gross weight of the filled barrel is determined by the
packing-room scales. The weight of the empty barrel is deducted and the
net weight of the sugar stenciled on the head. The full barrel is then
sent down a chute to the waiting freight car or to the dock for steamer
shipment, or to a conveyor that automatically delivers it to the storage
warehouse.
In addition to the bags, barrels, half barrels, cartons and boxes, tins
of various sizes are used for the different sugars. All of these are
filled and weighed automatically, and taken from the packing room by
conveyors. Some of the boxes are lined with paper and some with cotton
cloth; some are nailed up in the ordinary way, and others are strapped
with iron at each end. As a rule, the individual tins are cased with
wood, but sometimes there are a number of tins in a case. Cartons contain
two pounds, three pounds or five pounds of sugar. They are packed in
fiber cases holding thirty twos, twenty threes or twelve fives and also
in wooden cases which hold sixty twos, forty threes or twenty-four fives
each. The style of package depends upon the demand of the trade catered
to.
At this point a word or two about some of the specialties, such as cube,
powdered and bar sugars, as well as yellow or soft sugars, may be of
interest.
CUBE SUGAR
The sugar from which the cubes are made is of a rather fine grain, boiled
in special pans from liquor that has been filtered over the char at
least twice. From the centrifugals under the pan it falls into a hopper
in which there is a revolving screw. Directly over the screw is a tank
containing a warm, white sugar liquor, very sticky and viscous by reason
of its density. A pipe leads from the bottom of this tank to a point over
the screw, and the liquor, which is controlled by a valve, is allowed to
drip upon the sugar. The action of the screw causes the sugar and the
liquor to become thoroughly mixed and feeds the damp mass thus formed
into a spout leading to the cube press, the machine in which cube sugar
is made.
At the top of this machine is another hopper, into which the damp sugar
drops from the spout overhead, and revolving in the last-mentioned
hopper are a number of small shafts with brass pegs inserted at certain
intervals along the length of the shafts, like spokes in the hub of a
wheel. These pegs are like human fingers in their action and they press
the sugar down into the pockets of a large revolving drum placed directly
under the hopper. Each pocket is the size of a cube or half cube. Working
in these pockets are plungers, which fall back as the revolving drum
reaches the highest point directly under the mechanical fingers in the
hopper. The fingers fill the open pockets and, as the drum turns, the
plungers, at a certain point in its circumference where a heavy bronze
bar is placed across its face, slowly enter the pockets and in so doing
compress the sugar into cube form.
Two belts run through the machine under the cylinder, carrying galvanized
iron plates about twenty-four inches wide, or the same width as the
cylinder, and thirty inches long. As the line of pockets into which the
sugar has been pressed reaches the lowest point on the circumference of
the drum, the plungers drop down, forcing the pressed cubes out of the
pockets onto the galvanized iron plates which the moving belt carries
along out of the way of the next lot coming from the cylinder. Each
plate, as it leaves the cube press, contains five hundred and four cubes
and one hundred and sixty-eight half cubes, and the time required to fill
a plate is between six and seven seconds.
[Illustration: CUBE-SUGAR MACHINE]
[Illustration: CARTON MACHINE]
The belts carry the plates to a series of ovens, or driers, so placed
that a large number of plates with their contents may be inserted through
a door on the belt side. When the ovens are filled with plates holding
the soft, moist cubes, a current of hot air is turned on at the top of
the ovens, passing out at the bottom. The hot air circulating in this
manner dries the cubes and carries off the moisture. Eight hours in the
ovens suffice to render the cubes thoroughly dry and hard. They are then
removed through doors opposite to those through which they were put in.
This arrangement prevents the men who are putting the cubes into the
ovens from interfering with those taking them out, for the process is a
continuous one and cubes are placed in and removed from the ovens at the
same time. As the cubes are taken out of the ovens, they are deposited on
a belt conveyor which delivers them into bins in the packing room, ready
to be put into boxes, bags, barrels and other containers.
POWDERED AND BAR SUGAR
Powdered and bar sugars are made by grinding coarse granulated sugar
into fine particles and then separating these particles by screening
them through fine silk cloth. The bolting of flour is a similar process.
Powdered sugar has a decided tendency to cake and become hard, and the
coarse sugar from which it is ground should be particularly free from
moisture. After being crushed or ground between corrugated rolls turning
at high speed, the ground sugar passes into a screening or sifting
device, of which there are many kinds in use, the most common being the
horizontal, revolving centrifugal screen. The crushed sugar goes in at
the head end, and, as it enters, a number of revolving arms throw it
against a silk screen on a circular frame, revolving in an opposite
direction, that permits the finest, or powdered, sugar to pass through a
silk cloth having over sixteen thousand openings per square inch.
The powdered sugar extracted, the remainder drops into another screen
where a similar sifting action takes place, the silk of the second screen
being coarser than that of the first, and bar sugar is the result. Such
grains as are too large to pass through the bar screen are carried
back to the rolls and reground. The bar screen has about five thousand
openings per square inch.
Bar sugar, as the name implies, is generally used in preparing beverages.
It dissolves almost instantly when dropped in water. Singularly enough,
the average housewife is not aware of the advantages attending the use
of this grade of sugar. It does not become caked as readily as powdered
sugar does, and is the ideal sweetening for berries and cereals served at
the breakfast meal. It is far more desirable than powdered sugar for most
of the purposes for which the latter is commonly used.
It is believed by many that _all_ powdered sugar is adulterated with
chalk, starch, white corn meal or similar substances. Such is not the
case, and it is safe to assume that no mixing whatever is done by any
refiner in America. Powdered sugar has a strong tendency to cake or
become hard, and some manufacturers who buy coarse granulated sugar from
the refiners for grinding purposes use starch to the extent of from
two to three per cent. Chalk is never used, nor are other non-edible
or deleterious substances. Starch is not introduced for the purpose of
making a greater profit, but to prevent the powdered sugar from caking.
The adding of starch, in all probability, increases the cost of making
powdered sugar, as starch costs almost as much as sugar, and the expense
of handling it and feeding it into the grinding machinery is quite an
item.
[Illustration: FILLING, WEIGHING AND SEWING 2-POUND, 5-POUND AND 10-POUND
BAGS]
YELLOW SUGARS
Yellow sugars, or “softs” as they are usually called, comprise fifteen
grades, ranging in color from a creamy white to a dark brown. These
sugars are used chiefly by bakers in making gingerbread, pies and cakes,
although a small quantity finds its way directly into households for
ordinary domestic consumption.
The characteristics of yellow sugars are that they have a small grain
and contain a sufficient amount of molasses to make them moist to the
touch, properties brought about by a radically different method of
boiling from that applied to white sugars. They also contain a certain
amount of invert sugar which preserves the softness of grain and prevents
subsequent caking or hardening.
To properly explain how yellow sugars are boiled, reference must be made
to the method of boiling white sugars, which may be briefly summarized as
follows:
The object to be attained in boiling white sugars is the separation
of the crystallizable sucrose contained in a given solution from the
impurities, moisture and non-crystallizable content of that solution.
The formation of sugar crystals is a natural result of the evaporation
of the moisture from the liquor or solution. In order to obtain pure
white crystals, it is vitally essential that, as far as possible, all
impurities and non-sugars, except water, be removed from the liquor
before the boiling takes place, for if the coloring matter is not
thoroughly taken out, obviously the crystals will be colored. The
purifying and decolorizing operation is accomplished in the char filters.
After the grain is once formed in definite crystals, these crystals
attract and appropriate the sucrose in solution in the process of
building up their structure, while repelling or excluding the impurities,
so that in consequence the latter remain in solution. Irrespective,
however, of whether crystallization of sucrose takes place in solutions
of high or low purity, it will only partially remove the sucrose from the
solution in one operation, the limit being fixed by the amount and nature
of impurities present. In order to bring about further crystallization of
sucrose the solution or mother liquor surrounding the crystals must be
separated from them and be again diluted, filtered and concentrated.
Briefly, the procedure in boiling white sugar in a vacuum pan is to take
liquors of the highest purity for the first boiling. After the first
crystals have been removed from the mother liquor in the centrifugal
machines, the liquor is again diluted, decolorized by bone-char and
boiled to grain. This operation is continued a number of times, the
purity of the liquor decreasing each time. Finally, when the purity
of the liquor falls to a certain point, the boiling is discontinued,
for at this point conditions do not admit of further formation of pure
sucrose crystals, and, if the process were pursued further, the resulting
sugar would not be white. Therefore, when this state is reached, these
low-grade liquors are boiled into a semi-refined sugar, commonly called
“refinery raw,” which corresponds fairly closely in test with the
original raw sugar, or they are used for making soft yellow sugars as
explained later on. This refinery raw is then washed, melted and put
through the whole process all over again. The liquor, from which the
crystals formed in repeated boilings have been removed as made, at
length becomes so charged with impurities that further crystallization
of sucrose is impossible and this residue, or final waste, is known as
blackstrap molasses.
This manner of boiling white sugar has been called the “out and out”
method, in contradistinction to the “in and in” method employed in
boiling soft yellow sugars, of which a few words of explanation now
follow.
In boiling soft yellow sugars, the aim is to produce a large number of
small sucrose crystals having the property of attracting and combining
with the molasses content of the liquor and that will retain some of
the molasses after they are purged of mother liquor in the centrifugal
machines. This process gives a sugar that may be described as a
mechanical mixture of sucrose, invert sugar and the non-sugars in the
molasses.
In the case of yellow sugars, the lighter the color the better price they
bring. The greatest profit, therefore, is derived from the manufacture
of sugars of the lightest color and carrying a reduced percentage of
sucrose. In boiling such sugars, low-purity liquors from which the
coloring matter has been removed as far as practicable by bone-char
filtration are required. For the purpose, it is generally found most
advantageous to use the liquors taken from white sugar massecuite at the
point when, owing to repeated boilings, its purity has fallen so low that
further extraction of pure white sucrose crystals is impossible.
As a result of the numerous filtrations through bone-char preparatory to
reboiling in the manufacture of white sugar, these liquors are usually
lighter in color than any of corresponding purity obtained in the
refining process. Nevertheless, they are not necessarily the only liquors
suitable for the purpose, and this particularly applies to the making
of the lower grades of yellow sugars. It is, however, beyond the scope
of this book to elaborate upon that phase of sugar refining. The object
sought here is to give a general idea of how yellow sugars are boiled,
without going into all the details.
As is the case with white sugars, yellow sugars are made by a succession
of boilings in vacuum pans, the liquor used for each boiling or strike
being that obtained from the massecuite of the previous strike. The
operation is continued until the liquor becomes too low in purity and
dark in color. Each successive strike boiled is lower in test than the
preceding one, due to the fact that the sucrose crystals represent the
purest part of the massecuite, and, consequently, each time they are
removed the quality of the liquor is lowered. This accounts for the
various grades of yellow sugar that are made, fifteen in all, starting
with a creamy white and ending with a dark brown. The sucrose content of
the best is about 92 per cent and that of the poorest about 80 per cent.
In making white sugars, the aim is to produce from liquors of high purity
sucrose crystals that are pure white, hard and absolutely free from
molasses.
In making yellow sugars, the object is to boil from low-purity liquors
soft sucrose crystals that possess the property of attracting and
retaining the molasses and to make this combination of crystals and
molasses as complete as possible.
The essential difference between the two methods, as well as the
appropriateness of the descriptive terms “out and out” and “in and in,”
will be readily apparent.
The impurities in yellow sugars are natural and consist of invert sugar,
glucose, organic non-sugars and salts, all of which were originally
present in the raws or were formed in the process of refining.
It is not unusual to hear it said that yellow sugars are sweeter than
granulated. To the average palate this is apparently so, but, as has been
shown, granulated sugar contains 99.8 per cent of sucrose or sweetening
matter, while the highest grade of yellow carries only 92 per cent. Soft
sugars dissolve more readily on the tongue than granulated, and the syrup
or molasses in them accentuates their sweet taste.
There are several other grades of sugar prepared for the consuming
market, but lack of space precludes a description of them or the methods
by which they are produced.
MECHANICAL DEPARTMENT
It is needless to say that the conveying, melting, filtering, boiling,
drying, screening, weighing and packing of one thousand tons of sugar in
twenty-four hours necessitates a great amount of steam and a multiplicity
of machinery.
The boilers generate steam to drive huge pumps that deliver cold salt
water to the condensers throughout the refinery, to drive vacuum pumps
that make boiling and evaporation _in vacuo_ possible, and to drive large
turbine or reciprocating engines that supply the electric power. The
exhaust steam as it leaves the cylinders has a pressure of about fifteen
pounds per square inch. It is conducted through pipes to the evaporators,
pans, driers and tanks, where it is again used for concentrating the
liquors, boiling in the pans, drying the sugar and keeping the liquors
hot throughout the process. It leaves the various heating coils and tubes
as hot water and is returned to the boilers for the generation of more
steam.
Live steam, that is to say, steam just as it comes from the boilers, is
used extensively in the vacuum pans for boiling the liquor to grain.
A refinery melting one thousand tons of raw sugar each day requires about
5500 boiler horse power. On the Atlantic coast coal is the fuel used,
while on the Pacific coast oil is burned. The amount of fuel consumed in
different refineries varies to some extent, but a fair average per ton of
raw sugar melted is one and one-third barrels of oil, or one-third of a
ton of coal.
In modern plants all the moving machinery, except the pumps and main
engines, is usually driven by electric motors. This does away with many
dangerous belts, as well as expensive transmission machinery. The motor
drive is simple and efficient and therefore used extensively.
The mechanical department is under the general supervision of the
superintendent, but in direct charge of a mechanical-electrical engineer.
This man is known as the chief engineer, and he is directly responsible,
not only for the operation of all the machinery in the plant together
with its upkeep and repair, but he has also to cope with engineering
problems that are constantly arising. Under his direction, a corps
of draughtsmen is always busily engaged in planning and designing
improvements and additions. He also maintains a force of mechanics,
watching, operating and repairing the machinery. These men represent
almost every trade, including machinists, blacksmiths, coppersmiths,
tinsmiths, millwrights, boilermakers, riggers, masons, painters and many
others.
The diversity of the mechanical work around a refinery is remarkable, and
the engineer in charge must be a man of exceptional mechanical ability,
as his duties include not only steam, electrical and civil engineering,
but construction engineering of an advanced character. As refineries
are always built on sites bordering on deep water, harbor engineering
problems are also constantly before him.
In connection with every refinery there are many shops, where mechanical
work incidental to repairs and construction is carried on. These shops
are equipped with the necessary tools and implements for quick repairs
and are under the supervision of the chief engineer. In addition, there
is the cooper shop where many thousands of barrels are turned out daily,
and the bag factory where twenty cotton bags and twenty burlap bags must
be made for each and every ton of output packed in that manner.
The mechanical department of a modern refinery is as important as it is
extensive, for failure in any one of its branches means costly delays.
The machinery is run twenty-four hours each day, except Sundays, during
about eleven months in the year. The plant is closed down the remaining
thirty days for annual cleaning and repairs.
Intelligence and ability, tempered with good judgment, bring about the
_esprit de corps_ that gives the necessary results. The mechanical is
almost as important as the chemical department and, as before stated, it
is subject to the general supervision of the chemical engineer.
[Illustration: LABORATORY]
[Illustration: OIL-BURNING BOILER PLANT]
LABORATORY
The chemical laboratory is really the heart of the institution, for
upon it depends the success of every manufacturing operation. The
superintendent of a refinery must possess a thorough knowledge of
chemical engineering, for the process of sugar refining is largely
chemical from beginning to end.
Competent chemical engineers, as distinguished from chemists, are rare,
and yet their calling offers more promising prospects to young men than
most other professions do today. It is clear to the intelligent observer
that in these times of intensely keen competition, the manufacturer will,
sooner or later, inevitably be driven to seek a considerable percentage
of his profits in the utilization of by-products that now go to waste or
bring but little return. The men to solve the manufacturing problems of
the future will be chemical engineers. Broadly speaking, comparatively
little has been done in this field in the United States, and its
possibilities are incalculable.
In the laboratory, day and night, a corps of chemists is constantly
engaged in the study of questions that arise in connection with the
operation of the various departments. Polarizations for account of buyers
and sellers of all raw sugars purchased, are made and checked there;
hundreds of samples of liquors and syrups are tested daily for control
work, as the purity of both must be known at all times and a record kept
of their temperatures and densities. Samples of all the sugars entering
the refining process, as well as of the finished product, are carefully
analyzed, and upon these analyses are based elaborate calculations
regarding yield and efficiency. The wash waters from the char filters are
examined and tested frequently, the bone-char is tested every twenty-four
hours as a check upon the process of revivification in the kilns, and
once a month the bone-char is completely analyzed to determine the
deterioration that has taken place in it.
Tests are made of materials used in the refining process, such as lime,
soda, acids and lubricating oils; of the feed water for the steam
boilers; of the fresh water used throughout the plant; and of the fuel,
whether coal or oil. Even the gases from the fires under the boilers are
tested as they pass through the smokestack, in order to determine whether
or not the firemen perform their duties properly.
Taking all this in conjunction with frequent tests and experimental work
on driers, condensers, evaporators and other apparatus, it will be seen
that there is plenty to keep a large staff of chemists fully occupied.
In refinery work, what is to be feared more than anything is the house
becoming “sour.” Raw sugars and sugar liquors, and particularly the
sweet waters, have a tendency to ferment, and fermentation, like fire,
if not checked and brought under control before it gains much headway,
soon pervades the entire establishment, affecting all the liquors and
syrups, thus turning the sucrose or sugar into glucose, which cannot be
recrystallized. In a refinery of two million pounds daily capacity, there
is double this quantity of sugar in the house in the form of liquors,
syrups, sweet water, massecuite and raws. If all of this four million
pounds turned “sour,” the money loss, with raw sugar worth four cents
a pound, would be about one hundred and sixty thousand dollars. Such a
contingency, while remote, clearly demonstrates that chemical control is
an absolute necessity.
COST OF REFINING
In concluding that part of the story that deals with refining, some
reference may be made to the refining cost and to the price at which
refined sugar is sold.
The cost of refining sugar varies in different parts of the United States
on account of the difference in the cost of commodities entering into
the refining process, such as labor, fuel, cotton, burlap, containers,
bone-char, etc. On the Pacific coast nearly all these items are higher
than in New York, and consequently the cost of refining is probably
greater.
In 1911 nearly all the sugar refiners of the United States appeared
before the Hardwick Congressional committee at Washington and the
testimony given by them before that body showed that the cost of refining
ranged from 60 cents to 65 cents per 100 pounds.
On the day the Congressional committee began its investigation, raw sugar
was selling in New York for 3.86 cents per pound, and the testimony
regarding the cost of refining was no doubt based on this price for the
raw sugar entering the refining operations.
It is therefore fair to assume that under normal conditions, with raw
sugar at about 3¾ cents, the average cost of refining in the United
States is 62½ cents per 100 pounds. This includes every item from the
time the raw sugar is landed on the dock until the refined is loaded on
the cars or boats for shipment. It includes the selling and overhead
expenses, but not the transportation charges after the sugar leaves the
refinery.
During the last six years (1909-14 inclusive) the actual differential in
the United States between the purchase price of raw sugar and the selling
price of refined has been 82½ cents per 100 pounds. The difference
between this figure and the cost of refining represents the refiner’s
gross profit; in other words, about 20 cents per 100 pounds, out of
which he must pay for all additions and improvements to his plant. The
remainder is available for returns on capital invested. This difference
varies with the time of year and in different localities, but the average
will probably hold good.
A refiner of cane sugar buys his raw product in the open market and
must pay for all his operating and administration expenses and obtain
his profit from the margin between the buying price of raw and the
selling price of refined sugar. The cost of refining is not constant, as
it varies with the fluctuating values of fuel, containers, labor, and
particularly the cost of raw sugar. If it costs 62½ cents per 100 pounds
to refine sugar with raws at 3.86 cents per pound, it will cost about 82½
cents per 100 pounds with raw sugars at 6 cents, assuming that such items
as fuel, containers, labor, etc., remain constant. This is due to the
greater value of the raw sugar lost in refining, to the heavier insurance
premiums and higher interest charges. With high-priced raws, the margin
between raws and refined must be proportionately greater to offset the
increased cost of refining.
The refiner, like the consumer, would prefer to see sugar selling on a
low basis, while the producer always hopes for the opposite.
SHIPPING DEPARTMENT
Here will be found every modern convenience for the rapid loading of cars
and steamers. Adequate railway trackage is provided for the handling of
shipments moving by rail, and on the waterfront side of the warehouses
there is ample berth room for steamers that carry the sugar to cities
and towns on the inland waterways and the seacoast, together with points
tributary thereto. Facilities are also at hand for local delivery by
drays.
Railroad cars are sometimes sent to refineries by water, on car barges,
to be loaded with sugar and then towed to what are known as railroad
terminals, where the cars are taken from the barges and started on their
journey to destination. The capacity of a car varies from twenty-four
thousand to one hundred thousand pounds. If an amount of sugar equal
to that consumed in the United States in 1915 were loaded into cars
containing 1000 sacks of 100 pounds each, it would require 81,087 cars,
which would make up a train 768 miles long.
A large part of the product is delivered direct from the packing-room
conveyors into the waiting cars and steamers, thus avoiding unnecessary
handling. A single shipment frequently includes a number of different
styles of package, and great care must be exercised to insure accuracy in
count and description.
As dry granulated sugar readily absorbs moisture, every precaution must
be taken to make the storage rooms thoroughly damp-proof, so that the
sugar may always be in good condition when shipped from the refinery.
Shipments are made only on written orders from the sales department to
the head of the shipping department. These orders set forth the name of
the buyer, the kinds and quantity of sugar desired, the point to which
the sugar is to go, the route by which it is to travel, the date on which
it is to be shipped, and the terms of sale. At the proper time the sugar
is loaded, shipped, and in due course delivered to the buyer.
[Illustration: INLAND-WATERWAY STEAMER LOADING SUGAR AT REFINERY DOCK]
[Illustration: CAR-FLOAT ARRIVING AT REFINERY DOCK]
MARKETING
The amount of sugar used in the United States in 1915 was 4,257,714 short
tons. Of this, 3,389,175 tons were raw cane, the remainder consisting of
861,568 tons of domestic beet and 6,971 tons of foreign refined cane and
beet. Of the 3,389,175 tons of raw cane, 150,000 tons were consumed in
the raw state, and from the remainder, 3,239,175 tons, about 3,044,825
tons of refined sugar were produced. The per capita consumption was 83.83
pounds, and was made up of:
SHORT TONS PER CENT
Refined made from raw cane 3,044,825 74.94
Domestic and foreign beet 862,694 21.23
Foreign refined cane 5,845 .14
Consumed in the raw state 150,000 3.69
--------- ------
4,063,364 100.00
Among articles of food that contain a large percentage of sugar are jams,
jellies, chocolate, canned fruits, condensed milk, confectionery, chewing
gum and cordials. It is estimated by Willett & Gray that in 1915 the
direct per capita consumption was 31.43 pounds, and that the remaining
52.40 pounds were used in various prepared or manufactured foodstuffs.
Over ninety-nine per cent of all the cane sugar consumed in the United
States is refined in New York, Boston, Philadelphia, New Orleans and San
Francisco. The beet comes chiefly from California, Colorado, Michigan,
Utah and Idaho; the maple from the New England states, Ohio and Canada;
and the small amount of full duty-paying foreign cane from Java, Peru,
Mexico, Central America and Santo Domingo.
During the past eleven years the consumption in the United States has
grown at an average rate of 3.57 per cent per annum. In 1911, on account
of the abnormally high prices, the increase was practically nil.
The annual per capita consumption of sugar in some of the other countries
of the world is as follows:
1914
Servia 4.60 lbs.
Greece 8.99 ”
Bulgaria 9.94 ”
Italy 10.45 ”
Portugal 13.60 ”
Spain 15.91 ”
Roumania 17.12 ”
Turkey 20.33 ”
Russia 29.26 ”
Finland 32.54 ”
Austria-Hungary 37.38 ”
France 39.01 ”
Belgium 42.79 ”
Holland 53.44 ”
Norway 60.37 ”
Sweden 60.48 ”
Switzerland 74.87 ”
Germany 74.95 ”
England 89.69 ”
Denmark 93.48 ”
The sale and distribution of large quantities of refined sugar is a
serious problem and just as important as the production and the refining
of the raw product. Competition is so keen, and the questions involved
so complex, that the sale of the product really results in commercial
warfare.
To dispose of the output of a large plant successfully requires great
intelligence, a broad grasp of business principles, strict honor and
integrity, and prompt, decisive action in times of fluctuating markets.
Sales managers of the sugar-refining companies of the United States
command high salaries, for the success of the business depends to no
small extent upon their ability and judgment. Their knowledge of human
nature must be broad and sound and it is tested to the utmost in their
selection of assistants and brokers, for representatives always reflect
the ideals, principles and methods of the parent authority.
The selling of sugar by the refiner direct to the consumer has not been
found practicable, as an organization complete enough to keep in touch
with consumers in every city, town and village of the country would be so
top-heavy and costly to maintain that the price of the commodity to the
consumer would be needlessly increased.
As matters stand, people living in the frozen valleys of Alaska, in the
scarcely accessible regions of the Rocky mountains and in the lumber and
mining settlements of the West, many miles from railroads, can obtain
their supply of sugar with almost the same facility as the residents
of New York or San Francisco. A system of distribution that makes this
possible leaves little to be desired, and a word or two concerning it
will be timely at this point.
Sugar is sold by the refiner to the wholesale grocer through the medium
of the refinery’s broker. From the wholesaler it goes to the retailer,
who in turn delivers it to the consumer.
Brokers are important factors in distribution. In every large city and
consuming center, each refinery is represented by its own brokers, who
keep in constant touch with all the wholesale grocers and manufacturers
of their district.
A thorough knowledge of men and methods, sound business principles,
diplomatic talents of no mean order and the capacity to act rapidly, but
coolly, in business crises are found combined in the successful broker.
He occupies a position between the seller and buyer, and it is just as
much his prime duty to see that in all transactions full justice is
accorded to both as it is to sell the sugar.
Every refinery having its own broker in each consuming center, it follows
that the competition for business among the brokers is very keen. When a
broker obtains an order from a jobber or manufacturer, he telegraphs it
to his principal. The order is usually confirmed and the goods shipped
promptly. For his services the broker receives three cents for every
one hundred pounds of sugar sold. This compensates him for the services
of his salesmen and himself, his office expenses and cost of telegrams,
which is heavy.
Manufacturers of foodstuffs of which sugar is an ingredient, buy their
supplies through brokers. They do not resell the sugar as such, but use
it only in the manufacture of their own special products.
Wholesale grocery jobbers, of whom there are about twenty-five hundred in
the United States, are also very important factors in the distribution of
sugar. As a rule, they are located in the large centers of population,
and have efficient organizations for the purchase and resale of all
kinds of foodstuffs. They deal in as many as three thousand different
commodities, and their expense of doing business is apportioned over
all of these items, thus reducing to a minimum the expense of handling
any one of them. Generally speaking, they have large establishments
where stocks of all kinds of goods are carried ready for immediate
distribution. The aggregate capital tied up in these stocks throughout
the country is enormous, but necessary, as the jobber must at all times
be ready to deliver to the retailer whatever is wanted in any of his
lines. Wholesale jobbers occupy a unique position in the scheme of
things. They are to the commerce of the country what the bankers are
to its finances. In other words, they are the bankers of commodities.
Their operating staff consists, first, of the buyers, and, second, of the
salesmen.
The buyers are men possessing special knowledge concerning the various
articles handled by the house. For instance, in the grocery line one
will buy nothing but teas and coffees, another canned goods, another
sugar, and so on. These men as a rule have devoted years of study to the
particular commodity which they are delegated to buy. They are shrewd,
keenly alert and always ready to take advantage of market fluctuations in
their favor. The margin of profit between the buying and selling price
of any commodity is usually so small that the acumen of the buyer is an
important factor in the final results.
The salesmen are trained, tactful, tireless and efficient. They travel
from town to town and place to place, visiting every nook and corner
where human beings congregate, in order to sell the goods carried by the
firm. While his calling is a most useful one, the life of a “knight of
the grip” is not always pleasant, as he meets with many deprivations and
discomforts.
To compensate him for capital invested, for the expense of doing business
and for the losses he incurs in bad debts and declining markets, the
jobber probably obtains a gross return of fifteen cents on each one
hundred pounds of sugar he sells.
The next important link in the chain is the retailer. It is roughly
estimated that there are three hundred thousand retail grocers in the
United States, many of whom handle and distribute almost as many articles
as the jobber. Their lot on the whole is not cast in pleasant places,
because of the severe competition they meet in selling their goods.
Competition is a word regarded almost with affection by the buyer, but
for the seller of goods it is probably the most unpleasant one in the
English language. There is an old axiom which reads: “Competition is the
life of trade.” It may be so, but the expression was no doubt coined by a
buyer.
Among sellers, competition is in direct proportion to the number engaged
in any particular business. It therefore follows that as there are
three hundred thousand retailers in the United States, and hundreds in
each of all the large cities, the struggle to keep on their feet and
continue their various enterprises must be severe. The number of failures
occurring every year amply substantiates this assertion. Reckless and
unscrupulous men engage in every business, and the competition thus
forced on all others in their line is not only unfair, but positively
dishonest. Any individual can break a price or introduce new and
expensive experiments in selling terms, which must be followed with
equally attractive terms by the other sellers, thus resulting in great
loss to all. It is no satisfaction that such men finally fail and go
out of business, for the losses sustained in the interim can never be
recovered.
Another grave difficulty with which the retailer has to contend is the
fact that the average individual to whom he delivers his wares is apt to
be rather callous when pay-day comes around. It is sad, but true, that
those best able to pay are sometimes the most unsatisfactory customers of
the retail grocer.
A retailer’s expense of doing business is proportionately much greater
than that of the wholesaler, and his losses, due to bad or uncollectible
accounts, are much heavier. The cost of delivering goods to the
consumer’s door is high, and a fact that should be remembered, but which
is frequently overlooked, is that it costs the grocer just as much to
deliver a five-pound package of sugar as a wagon-load. Householders are
proverbially careless, and telephone calls for late and urgent deliveries
are a source of great annoyance and expense.
To create a pleasing impression, the grocer must keep a clean, sanitary
store, and the expense incident to attractive window and shelf displays
to invite attention is an important item. Department and other stores
in his town or neighborhood often advertise “leaders” to attract the
buying public, in the hope of selling with these leaders other goods at
a profit, or because they are overstocked with a particular commodity.
Every retailer must, as a rule, meet this unfair competition or lose his
trade.
Sugar more than any other staple article is used as a leader, and, as
a result, the retail grocer’s profit on it is very small. What remains
to him out of the selling price of one hundred pounds of sugar does
not exceed thirty-five cents, and more than likely it has cost him
twenty-five cents to sell it. It is the retail grocer’s employé who
delivers sugar in the quantity desired to the housewife at her door, and
through her hands the pure, glistening crystals reach the family table.
BEET SUGAR
SHORT REVIEW OF THE HISTORY OF BEET SUGAR
The extraction of sugar from beets dates back to 1747, when Andreas
Marggraf, professor of physics in the Academy of Science of Berlin,
discovered the existence of a sugar in beets similar in its properties to
that obtained from cane.
The discovery was little utilized at first, however, and the manufacture
of sugar from beets did not attain commercial importance for over half a
century, when Franz Karl Achard, a pupil of Marggraf, made discoveries
which led to the construction of the first beet-sugar factory in the
world, in Silesia, in the year 1799.
The work of Achard soon attracted the attention of Napoleon Bonaparte,
who appointed a commission of scientists to go to Silesia to investigate
Achard’s factory. Upon their return, two small factories were constructed
near Paris. Although these two factories were not altogether a success,
the results attained greatly interested Napoleon, and in 1811 he issued a
decree appropriating one million francs ($200,000) for the establishment
of sugar schools, and compelling the farmers to plant a large acreage
to sugar beets the following year. He also prohibited the further
importation of sugar from the Indies after January 1, 1813.
As a result of these and other drastic decrees, three hundred and
thirty-four factories were erected in France during the years 1812 and
1813, and their production was seven million seven hundred thousand
pounds of sugar, or an average of eleven and one-half tons to the
factory.
[Illustration: _By permission of Truman G. Palmer, Esq._
SUGAR BEET]
[Illustration: _By permission of Truman G. Palmer, Esq._
ANOTHER TYPE OF SUGAR BEET]
With the fall of Napoleon Bonaparte, disaster came upon this, one of his
greatest achievements, and but one factory survived. The industry was
destined to flourish again, however, under the reign of Louis Philippe.
In 1836-37 there were five hundred and forty-two factories in France,
producing thirty-five thousand tons of sugar, as compared with fourteen
hundred and eight tons in Germany, which country had only recently begun
the culture of beets.
When Napoleon III became emperor, he so stimulated the industry that in
1853 the French output had doubled. Meanwhile the Germans were making
rapid strides, and in 1880 the German output of sugar exceeded that of
France. As a result of legislative encouragement, Germany today is the
largest beet-sugar producer in the world.
The first successful beet-sugar factory in the United States was
constructed by E. H. Dyer, at Alvarado, California, in 1879. The next
successful factory was erected at Watsonville, California, in 1888, by
Claus Spreckels. The Oxnard brothers followed with the construction in
1890 of a factory at Grand Island, Nebraska, one at Norfolk, Nebraska,
and a third at Chino, California, the last built in 1891.
From this it will be seen that the commercial production of beet sugar
in the United States really dates back to about 1890, since only three
factories of small capacity had been established prior to that date. The
development of the industry since the year 1892 has been rapid, and the
general results of the beet industry in the United States in 1915 showed
the following:
Factories in operation 67
Acres of beets harvested 611,301
Average yield of beets per acre 10.10 short tons
Beets worked 6,150,293 ”
Sugar manufactured 874,220 ”
The season of 1916 promises a notable increase in tonnage.
THE SUGAR BEET
The botanical name of the sugar beet is _Beta vulgaris_. It grows
exclusively in the temperate zone, and with satisfactory soil and
climatic conditions a yield of thirty tons per acre has resulted. The
average yield in the United States, however, is slightly over ten tons
per acre. There are many varieties of beets, some of which do better
in one locality than another, so that great care must be used in the
selection of the seed.
The beet, unlike sugar cane, grows below the ground, is white in color
and shaped like the ordinary carrot, but larger. The beets vary greatly
in size, depending upon variety, soil and climatic conditions, the
average weight ranging between one and two pounds.
The foliage has a rich, brilliant green color and grows to a height of
about fourteen inches. The leaves are numerous and broad and grow in a
tuft from the center or crown of the beet, which is usually level with or
just above the ground surface.
The average composition of a sugar beet is about as follows:
Sugar 17.3 per cent
Marc or pulp 4.4 ”
Ash and organic non-sugar .7 ”
Water 77.6 ”
The value of the beet to a factory depends on the amount and purity
of the sugar content. Factories as a rule decline to purchase beets
containing less than twelve per cent of sucrose, as it is unprofitable
to handle them. In order to induce the farmer to devote particular care
and attention to the culture of his fields and thus increase the sugar
content, the factories pay a premium for beets containing over fifteen
per cent of sugar. The premium is usually twenty-five cents per ton of
beets for each additional one per cent of sugar. Encouraged by this
bonus, the California grower has improved the quality of his beets,
until today they contain on an average about eighteen per cent of sugar
of a purity from eighty to eighty-four.
[Illustration: _By permission of Truman G. Palmer, Esq._
PLOUGHING WITH CATERPILLAR ENGINE]
[Illustration: _By permission of Truman G. Palmer, Esq._
PLANTING BEET SEED]
SELECTION OF THE SOIL
The sugar beet, like sugar cane, needs a peculiar soil and climate for
its successful cultivation. The most important requirement is that the
soil shall contain a large supply of plant food, be rich in humus and
have the property of retaining a great deal of moisture. A certain
amount of alkali is not necessarily detrimental, as sugar beets are not
especially susceptible to injury from this salt. The ground should be
fairly level and well drained, especially where irrigation is practiced.
While the physical character is of secondary importance, as generous
crops are grown in sandy soil as well as in heavy loams, still the ideal
soil is a sandy loam, _i. e._, a mixture of organic matter, clay and
sand. A subsoil of gravel, or the presence of hard-pan, is not desirable,
as cultivation to a depth of from twelve to fifteen inches is necessary
to produce the best results.
Climatic conditions, temperature, sunshine, rainfall and winds have an
important bearing upon the success of beet culture. A temperature ranging
from 60 degrees to 70 degrees Fahrenheit during the growing months is
most favorable. Sixteen inches of rainfall are necessary to raise an
average crop of beets without irrigation. High winds are very harmful,
as they generally crust the land and prevent the young beets from coming
through the ground. The best results are obtained along the coast of
southern California, where warm, sunny days succeeded by cool, foggy
nights seem to meet every requirement. Sunshine of long duration but
not of great intensity is the most important factor in the successful
cultivation of sugar beets. The nearer the equator is approached, the
poorer the beets become in sucrose because of the shorter days and the
greater heat of the sun. Beets have never been raised with success in
the hot interior valleys, as the hot days followed by warm, dry nights
sap the vitality of the plant. In the elevated Rocky mountain region of
Colorado and Utah, where the temperature is high during the daytime but
where the nights are cool, the quality of the beet is excellent.
In Michigan the long summer days and the influence of the great lakes
result in satisfactory climatic conditions for sugar-beet culture, and
the crops raised in that state are large.
In order to cultivate beets successfully the land must be properly
prepared. Deep ploughing is the first principle of beet culture. It
allows the roots to penetrate the subsoil without much obstruction,
thereby preventing the beet from growing out of the ground, besides
enabling it to extract considerable nourishment and moisture from the
lower soil. If the latter is too hard, the roots will not penetrate it
readily and, as a result, the plant will be pushed up and out of the
earth during the process of growth. A hard subsoil is impervious to water
and prevents proper drainage. It should not be too loose, however, as
this allows the water to pass through more freely than is desirable.
The character of the surface soil is equally important. Careful
preparation by harrowing should be done to afford a finely pulverized and
clean bed for the seed.
To sum up, the soil should be deep, fairly fine and easily penetrable by
the roots. It should also be capable of retaining moisture and at the
same time admit of a free circulation of air and good drainage.
PLANTING
The preliminary preparation of the ground finished, the seed should
be put in as soon as the soil is firm enough to allow it to germinate
readily and the young plants to grow normally. The time of planting
varies according to climatic conditions. In California planting begins
as a rule in December and ends in March, while in Utah, Colorado and
Michigan it ranges from March until May.
[Illustration: _By permission of Truman G. Palmer, Esq._
THINNING]
[Illustration: _By permission of Truman G. Palmer, Esq._
CULTIVATING]
About twenty pounds of seed to the acre are required to produce a
satisfactory stand. The seed is planted in rows, about eighteen inches
apart, and is drilled in solidly to a depth of from three-quarters to one
and a half inches. The latter is the maximum, as any greater depth than
this weakens the plant and should, therefore, be avoided. The soil around
the seed is well packed by the planter in order to draw the moisture
necessary for germination.
The production of beet seed presents many problems; the chief one is to
obtain the particular kind of seed that will bring forth a hardy beet
containing a large percentage of sugar of a high purity. The beets from
which the seed is produced are selected with the greatest care, and for
nearly a century the Luther Burbanks of Europe have devoted their time
and skill to improving the quality. Until recently, practically all
of the beet seed used in the United States was imported from Europe.
Since the outbreak of the great war in 1914, however, the difficulties
attendant upon securing a supply have caused the beet growers to turn
their attention to raising seed in this country. Their efforts have been
rewarded with a fair measure of success, and while the cost is greater
than that of European seed, the germinating properties have proven to be
excellent. The best results have been obtained in Idaho. Owing to the
fact that the culture of the beets and the picking and sorting of the
seed are done chiefly by hand, labor enters largely into the cost of
production, and consequently, under normal conditions, the growers in the
densely populated countries of Europe have a great advantage over those
in the United States, where the main difficulty is securing labor for the
field work.
Like sugar cane, beets are subject to plant diseases of various kinds, as
well as to injury by insect pests, and great care has to be exercised to
ward off these dangers.
Probably no other crop exhausts the soil so rapidly as beets, and, if
they are planted for many years in succession, they deteriorate year by
year. On the other hand, if crops are rotated so that beets are grown in
the same ground every third year, peas, beans or grain being raised the
other two years, it is a remarkable fact that all of these crops will
improve each year. This is due to the intensive cultivation of the beets
and to the humus left in the ground in the form of rootlets. Experience
has taught the farmer that no other crop is so beneficial to the soil as
beets grown in the right rotation and with proper care.
THINNING
As soon as the beets are up and the rows clearly defined, thinning
becomes necessary. This is one of the most important features of beet
culture and is a tedious and expensive operation. It consists of cutting
out the plants so that individual roots remain, spaced about eight
inches apart. The work is done by hand, a hoe being used to block out
the spaces, and the roots surrounding the one which it is desired to
retain are pulled up. Due partly to faulty germination, but principally
to defective thinning of the beets, in which operation a great many of
the small, tender beet plants are injured or killed, very much less than
the theoretical number of mature beets are secured per acre. With rows
eighteen inches apart and a plant every eight inches in the row, 43,000
beets per acre should be obtained, which, at an average weight of one and
one-half pounds per beet, would mean 32.25 tons. Owing, however, to the
facts just mentioned and to other causes, the actual yield is always much
less. The average in California for a number of years past has been only
10.68 tons per acre.
[Illustration: _By permission of Truman G. Palmer, Esq._
FIELD OF RIPE BEETS]
[Illustration: _By permission of Truman G. Palmer, Esq._
TOPPING BEETS]
CULTIVATION
The purpose of cultivation is two-fold; first, to retain the moisture in
the soil, and, second, to destroy the weeds and grass, as in the early
stages of the growth of the beets weeds might spoil the stand by choking
the plants.
Cultivation should be continued until the plants have attained such a
size that the leaves cover the ground. It increases the fertility of
the soil by opening the land to the atmosphere, thus facilitating the
penetration of oxygen and absorption of air moisture and the resulting
decomposition and assimilation of nutritious elements.
HARVESTING AND TOPPING
The time when harvesting takes place depends on the many factors that
influence the growth and maturing of the beet. In the colder countries
the harvesting lasts from September until the ground becomes frozen,
while in warmer climates like that of California, where the seed is
planted early, harvesting begins about July first and lasts for a period
of from seventy-five to ninety days.
The beets are first loosened by means of a specially shaped plough,
called the “puller,” which lifts them from the ground. They are then
picked up by hand and the crown of each beet, together with the leaves,
is cut off with a large knife. The leaves contain no sugar, and are,
therefore, not taken into the factory, but are utilized for stock
feeding, being quite valuable for this purpose. The sugar contained in
the crown is accompanied by so many organic salts that it does not pay to
extract it.
The topped beets are then loaded into wagons or railroad cars and
transported to the factory, at which point they are carefully weighed.
In this country most of the beets are raised by farmers and sold under
contract to the factories, at so much per ton, so that the determination
of the exact weight and sucrose content is important. For the season of
1915 the average price paid to the farmers for beets was $5.67 per ton.
On arrival at the factory a certain number of beets are taken from
every wagon- or car-load, and these represent a fair average of all the
beets of that particular delivery. They are sent to the laboratory and
their exact weight ascertained, after which they are trimmed of all
adhering roots, leaves and parts of the crown, if not properly topped
in the field. Any remaining soil is carefully brushed off and the beets
thoroughly cleaned. They are then reweighed and the difference between
this and the first weight is the tare. This difference represents a
certain percentage of the total of the sample beets weighed, and that
small percentage is deducted from the gross weight of the total load.
In this way the exact net weight of beets delivered by the farmer is
determined and he is paid according to this net weight.
The sugar content of the beet and the purity of the juice must now be
ascertained, for the price paid the farmer varies according to the amount
of sugar the beet contains. As in the case of weighing, sampling and
polarizing raw cane sugar, representatives of both parties—the farmer and
the factory—are present when all weights are taken and tests made. There
are several different methods for determining the percentage of sugar in
the beet and the purity of the juice, but the following gives a fair idea
of the general practice.
The sample beets having been cleaned, are cut into quarters, one-quarter
of each beet being taken for the general sample. This general sample is
placed in a grinding or shredding machine, the beets are disintegrated
to a fine pulp and thoroughly mixed. A specific amount of this fine pulp
is then accurately weighed and placed in a copper pan or dish called a
capsule. A small quantity of dilute lead solution is introduced to assist
in clarifying, and sufficient water added to bring the volume up to
200 cubic centimeters. It is then heated for about twenty minutes and
vigorously agitated, so that the sugar-bearing juice of the beet will mix
evenly with the water that was added. The mixture, after being allowed to
stand for several minutes, is filtered through paper and a certain amount
placed in the observation tube of a polariscope. The instrument will show
the amount of sugar in the solution, and by multiplying the reading by
two the per cent of sugar in the beets will be found. If in preparing
the sample only sufficient water had been added to bring it to a volume
of 100 cubic centimeters, the polariscope would give a direct reading of
the percentage of sugar in the beets. Practice has demonstrated, however,
that the method described is the more accurate.
[Illustration: _By permission of Truman G. Palmer, Esq._
HAULING BEETS]
[Illustration: _By permission of Truman G. Palmer, Esq._
DELIVERING BEETS TO THE FACTORY BY WAGON]
To ascertain the purity of the juice, the procedure is as follows: A part
of the shredded sample is taken and the juice is squeezed out of it. The
amount of sugar in this juice is determined by aid of the polariscope,
and a Brix spindle shows the amount of solids it contains. By dividing
the polarization by the Brix and multiplying by 100 the purity is
obtained, which means the percentage of pure sugar in the total amount of
solids contained in the solution.
The purity of the juice has an important bearing on the subsequent
manufacture of the sugar. It is difficult and costly to extract sugar
from low-purity juices, and the loss of sugar in the process is very
high. The reverse is naturally true if the juices have a high purity. The
purity of the juice in the beet is materially affected during the growing
period by climatic conditions, rainfall, irrigation, fertilization, state
of soil and cultivation. Great care and attention must be given the beet
to insure high purity and heavy content of sugar.
From the above it will be seen how the net weight and the percentage of
sugar in any particular wagon- or car-load of beets are ascertained, as
well as the purity of all the beets that enter a factory. The efficiency
of the work in a factory is based on the figures thus obtained.
MANUFACTURE OF BEET SUGAR
The process of making sugar from the beet is highly technical in its
details and cannot be fully discussed within the scope of this work. A
brief description, however, will give an idea of the general methods
followed.
The process of manufacture may be classified under seven headings:
1. Transportation and cleaning of beets.
2. Extraction of juice, slicing and diffusion.
3. Purification, carbonation, filtration, concentration and
sulfitation.
4. Formation of grain.
5. Partial drying, purging crystals from syrup in centrifugals.
6. Final drying.
7. Packing.
TRANSPORTATION AND CLEANING
The beets, after delivery to the factory, are stored in V-shaped bins, in
the bottom of which is a flume covered by removable boards. By removing
the boards, one at a time, the beets are fed into the flume, where a
swift current of water floats them into the factory. From this flume the
beets are lifted by means of a large wheel, a helical screw or any other
suitable device, and discharged into a washer.
The common form of washer consists of a horizontal, semi-cylindrical tank
provided with rotating, kicking or stirring arms for keeping the beets in
motion. In this tank the beet is completely cleaned and separated from
adhering earth, weeds and pebbles.
[Illustration: _By permission of Truman G. Palmer, Esq._
DELIVERING BEETS TO THE FACTORY BY TRAIN]
[Illustration: _By permission of Truman G. Palmer, Esq._
GENERAL INTERIOR VIEW OF BEET-SUGAR FACTORY—SHOWING FILTER PRESSES IN
FOREGROUND; PANS AND EVAPORATORS IN REAR]
The beets are delivered from the washer into an elevator, which takes
them to a point near the top of the factory and discharges them into
automatic weighing and recording scales. From the scales the beets fall
by gravity into the slicing machines.
EXTRACTION OF JUICE, SLICING AND DIFFUSION
The slices are made in various shapes and forms. The slicing machines
consist of revolving, corrugated knives which cut the beets into long,
thin slices or “cossettes.” The object is to produce slices which expose
the greatest amount of surface, and yet sufficiently firm to lie not too
closely together when placed in the diffusion battery, thereby preventing
the circulation of the diffusion liquors. The cossettes are conveyed
on an endless belt, or through a hopper, to the cells of the diffusion
battery.
As the term implies, the juice in the beet is extracted by diffusion, and
not by crushing, as in the case of cane. When two liquids, separated by
a membrane, are brought in direct contact with each other and allowed to
stand for a time, they mix uniformly without the assistance of mechanical
or other force.
Beets are made up of a great number of plant cells, the walls of which
are porous membranes. These cells are placed in contact with water or
juice of lesser sugar content than the juice in the plant cell, in
consequence of which the juice is gradually diffused from the beet and
carried away in the circulating water which is added. When this water, or
rather juice, has reached a certain stage of concentration, it is drawn
out of the cells and sent to the next stage in the process of manufacture.
A diffusion battery, or the apparatus in which the process of diffusion
is carried on, consists of a number of tanks or cells, usually from ten
to fourteen, cylindrical in shape and terminating in truncated cones
provided with covers. There are two ways of arranging the cells of a
diffusion battery; in the one case the cells are placed in a straight
line; in the other they are grouped in a circle. These cells are filled
with cossettes in rotation, and water is introduced into the one in which
the cossettes were first placed.
Thus the water enters the tank in which the cossettes are nearly
exhausted of their sugar, and it flows successively through the other
cells that contain cossettes of greater sugar content until the last
cell, or the one containing fresh cossettes, is reached. The juice
passing through this cell is alternately sent to the measuring tank or
to the next cell, which has just been filled with fresh cossettes. The
process is continuous, one cell being emptied of exhausted cossettes
while another is being filled with fresh ones, and the juice flowing
either to the measuring tank or to the freshly filled cell.
The exhausted cossettes, now called pulp, are dropped from the bottom of
the diffusion tanks into a large bin, from which they are conveyed or
pumped to pulp separators and presses for the separation of the surplus
water. This pressed pulp is usually stored in large bins or silos, where
it is allowed to ferment before being fed to cattle.
Recently the practice of drying the pulp has been carried on to a large
extent. In this process the moisture in the pulp is reduced to ten per
cent, the same proportion as in cured hay. Dried to this point, it
is packed in bags and may be stored for an indefinite period without
deteriorating. After being treated thus it forms an excellent stock food,
particularly if waste molasses is sprayed on it before drying.
PURIFICATION OF JUICE, CARBONATION AND FILTRATION
The diffusion juice obtained as above described is quite dark in
color, and after passing through the measuring tanks it is conveyed to
carbonation tanks where it is treated with from three to four per cent of
caustic lime in the form of a thick milk.
[Illustration: _By permission of Truman G. Palmer, Esq._
DIFFUSION BATTERY—SHOWING DIFFUSION CELLS IN CIRCULAR ARRANGEMENT]
[Illustration: _By permission of Truman G. Palmer, Esq._
DIFFUSION BATTERY—SHOWING DIFFUSION CELLS IN STRAIGHT LINES]
After being thoroughly agitated, the mixture is treated with carbonic
acid gas obtained from the lime-kilns, as the result of the decomposition
of limestone and the combustion of the fuel used for burning it.
By this process some of the impurities in the juice are removed and the
color reduced to a brilliant amber. As is the case in the cane mills
and refineries, it is essential to keep the juice hot throughout the
process. The carbonation is continued until the juice is only slightly
alkaline, when it is passed through filter presses for the removal of
the precipitated lime carbonate and other solid matter. The solid matter
in suspension is retained in the frame of the press, and, as soon as the
frame is full, the cake is washed by passing water through it. When the
sugar content of the cake has been sufficiently reduced, the press is
opened and the cake discharged and sent to the fields to be used as a
fertilizer.
As a rule, the filtration is repeated for the elimination of any solids
that may have passed through the first filtration. This double filtration
is usually practiced in all the filtrations in the course of the juice
through the factory.
The juice after being filtered a second time is again treated with
carbonic acid gas for the further reduction of the caustic lime and
then undergoes a third filtration, following which it is sent to the
evaporators for concentration.
CONCENTRATION OF JUICE
When the juice reaches the evaporators it contains about eighty-two
per cent of water, which, by concentration, must be reduced to about
forty per cent. As already explained, the removal of water is generally
accomplished in multiple-effects. The apparatus consists of a number of
boiling bodies connected in such a manner as to secure a progressive
decrease in atmospheric pressure.
The thin juice enters the first body where evaporation takes place
under a slight pressure. The steam for this evaporation is usually the
waste or exhaust from the engines and pumps. The vapors generated by
the evaporation of water from the juice in the first body enter the
heating tubes of the second body and are used in further concentrating
the somewhat concentrated juice from the first body. The evaporation in
this second body is conducted at a higher vacuum and corresponding lower
temperature than in the first body. This proceeding is continued until
five or even six bodies are used in the series. The last body is usually
under a vacuum of about twenty-six inches of mercury.
It is obvious that by this arrangement the concentration of the thin
juice is effected with the maximum of economy, direct steam being
admitted into the first body only and the rest of the operation
accomplished by the steam generated in the boiling of the juice.
SULFITATION
The thickened liquor leaving the last body of the evaporators is sent
to the sulphur station and treated with sulphur fumes, in order to
further precipitate the soluble impurities and reduce the color of the
liquor. It is then heated to boiling point in closed tanks and passed
through a double set of cloth filters. This is the final process in the
purification of the beet juice, and it is then ready for graining.
In a cane-sugar refinery no sulfitation of the liquor takes place, and
in a beet factory there is no char filtration for removal of color and
impurities in the liquor. These two points constitute the main difference
in the methods of making white sugar from the cane and the beet in the
United States. In Europe, however, many factories make a raw beet sugar,
which is subsequently refined with the aid of bone-char.
[Illustration: _By permission of Truman G. Palmer, Esq._
WEIGHING, FILLING AND SEWING BAGS IN A BEET FACTORY]
[Illustration: _By permission of Truman G. Palmer, Esq._
CATTLE FEEDING ON BEET PULP]
FORMATION OF GRAIN
The formation of the crystallized grain and its progress through the
vacuum pans, centrifugals, driers, granulators and screens, and into
the bags in the packing room, is identical with the process in a cane
refinery, which has already been described.
STEFFEN PROCESS
In some of the beet factories the sugar left in the final molasses is
extracted by what is known as the Steffen process. The final low-purity
molasses is diluted with water and cooled to a very low temperature,
after which finely powdered lime is constantly added to the solution at a
uniform and slow rate. The sugar combines with the lime and a saccharate
of lime is formed which is insoluble in the liquid. The suspended matter
or saccharate is then separated and washed in filter presses.
The cake from these filter presses, which is the saccharate of lime, is
mixed with sweet water to a consistency of cream and takes the place of
milk of lime in the carbonation process. When the Steffen process is
employed, about ninety per cent of the sugar originally in the beet is
extracted. The loss of sugar that does take place is accounted for in the
exhausted cossettes or pulp, in the pulp water which surrounds them when
they are dumped from the diffusion cells, in the cake and wash waters
from the carbonation presses and in the waste and wash waters from the
Steffen process. As the water used in washing the saccharate press cake
is rich in fertilizing qualities, it is used for irrigating the lands
adjoining the factory.
The 6,511,274 tons of beets harvested in the United States during the
season of 1915 contained an average of 16.49 per cent of sucrose, of
which 14.21 per cent found its way into the sacks as white sugar. The
difference, 2.28 per cent, represented the loss in working up the beets.
As only a few factories, however, were using the Steffen process, a
considerable amount of sugar was left in the waste molasses. For the
same period, the beets produced in California contained 17.82 per cent
of sugar, of which 15.64 per cent found its way into the sacks, showing
a loss of only 2.18 per cent. This may be accounted for by the fact that
probably more of the California factories were equipped with the Steffen
process than the average for the United States, and that the purity of
the juices of California beets was higher than the average for the United
States.
A factory equipped with the Steffen process and running on beets
containing 17.82 per cent sugar, with a purity of 82, should lose not
over 1.9 per cent of the sugar in the beet. The same factory without the
Steffen process would probably lose 5.04 per cent of the sugar.
It is interesting to know that, according to the testimony given before
the Hardwick committee, the average cost of producing and selling one
hundred pounds of white beet sugar in the United States today is about
three dollars and fifty cents. The selling price, which is from ten
to twenty cents per one hundred pounds less than the selling price of
refined cane sugar, fluctuates with the value of raw cane sugar. For
instance, if raw cane sugar is selling in New York at four dollars per
one hundred pounds, the selling price of refined cane will probably be
four dollars and eighty cents. Beet sugar, therefore, would be four
dollars and seventy cents or four dollars and sixty cents. On the other
hand, if raw cane were selling for three dollars per one hundred pounds,
refined would probably be three dollars and eighty cents and beet sugar
three dollars and seventy or three dollars and sixty cents. In the one
case the beet factory makes a large profit; in the other a very small
profit.
As the value of raw sugar is determined absolutely by the law of supply
and demand in the world’s markets, it is clear that the fortune or
misfortune of the beet-sugar producer is beyond his control.
[Illustration: _By permission of Truman G. Palmer, Esq._
THE FIRST SUCCESSFUL BEET-SUGAR FACTORY IN AMERICA—ALVARADO, CALIFORNIA]
[Illustration: _By permission of Truman G. Palmer, Esq._
A MODERN BEET-SUGAR FACTORY]